Pressure & altimetry
Explore how pressure, temperature and your altimeter fit together.
In one minute
Pressure decreases with height Less air above you means less weight pressing down.
ISA is a reference 15 °C and 1013.25 hPa at sea level; a lapse rate of 6.5 °C/km in the troposphere.
A setting changes the datum The altimeter converts static pressure into an indicated altitude.
Why does pressure fall as you climb?
Build the picture one step at a time, then compare the pressure at different heights.
What does the standard atmosphere predict?
Change altitude and outside air temperature. Compare today’s temperature with the ISA reference.
Where are you, and what does the instrument say?
Change the pressure setting, the weather and the aircraft’s true altitude. Watch the two positions separate.
Can the same pressure level sit at different heights?
Turn the 3D scene. The pressure surface is lower over cold air. Heights are exaggerated to make the relationship visible.
Which reference are you using?
Reveal the cards, then sort each description into its correct category.
Can you explain what changes?
Four original practice questions. Each answer comes with a reason.